At present, demands on performance of the display screen have become higher and higher. Take the display screen of an active matrix organic light emitting diode (AMOLED) for example, in order to add a fingerprint unlocking function to the display screen, a photosensitive module is generally used, and the photosensitive module is adhered on a back surface of the display screen by an optically clear adhesive (OCA) layer.
The photosensitive module generally includes a sensing layer and a collimating optical fiber layer on a glass or a thin-film layer, and the sensing layer, the collimating optical fiber layer and the OCA layer are sequentially stacked. Since the glass plate in the photosensitive module has good heat conduction, heat distribution in an area with the photosensitive module and other area of the display screen is non-uniform, and thus the display screen may display obviously non-uniform brightness when the display is lightened.